skimage2.morphology.skeletonize

skimage2.morphology.skeletonize(image, *, method=None)

Compute the skeleton of the input image via thinning.

Parameters:

image(M, N[, P]) ndarray of bool or int

The image containing the objects to be skeletonized. Each connected component in the image is reduced to a single-pixel wide skeleton. The image is binarized prior to thinning; thus, adjacent objects of different intensities are considered as one. Zero or False values represent the background, nonzero or True values – foreground.

method{‘zhang’, ‘lee’}, optional

Which algorithm to use. Zhang’s algorithm [Zha84] only works for 2D images, and is the default for 2D. Lee’s algorithm [Lee94] works for 2D or 3D images and is the default for 3D.

Returns:

skeleton(M, N[, P]) ndarray of bool

The thinned image.

See also

medial_axis

References

[Lee94]

T.-C. Lee, R.L. Kashyap and C.-N. Chu, Building skeleton models via 3-D medial surface/axis thinning algorithms. Computer Vision, Graphics, and Image Processing, 56(6):462-478, 1994.

[Zha84]

A fast parallel algorithm for thinning digital patterns, T. Y. Zhang and C. Y. Suen, Communications of the ACM, March 1984, Volume 27, Number 3.

Examples

>>> X, Y = np.ogrid[0:9, 0:9]
>>> ellipse = (1./3 * (X - 4)**2 + (Y - 4)**2 < 3**2).astype(bool)
>>> ellipse.view(np.uint8)
array([[0, 0, 0, 1, 1, 1, 0, 0, 0],
       [0, 0, 1, 1, 1, 1, 1, 0, 0],
       [0, 0, 1, 1, 1, 1, 1, 0, 0],
       [0, 0, 1, 1, 1, 1, 1, 0, 0],
       [0, 0, 1, 1, 1, 1, 1, 0, 0],
       [0, 0, 1, 1, 1, 1, 1, 0, 0],
       [0, 0, 1, 1, 1, 1, 1, 0, 0],
       [0, 0, 1, 1, 1, 1, 1, 0, 0],
       [0, 0, 0, 1, 1, 1, 0, 0, 0]], dtype=uint8)
>>> skel = skeletonize(ellipse)
>>> skel.view(np.uint8)
array([[0, 0, 0, 0, 0, 0, 0, 0, 0],
       [0, 0, 0, 0, 0, 0, 0, 0, 0],
       [0, 0, 0, 0, 0, 0, 0, 0, 0],
       [0, 0, 0, 0, 1, 0, 0, 0, 0],
       [0, 0, 0, 0, 1, 0, 0, 0, 0],
       [0, 0, 0, 0, 1, 0, 0, 0, 0],
       [0, 0, 0, 0, 1, 0, 0, 0, 0],
       [0, 0, 0, 0, 0, 0, 0, 0, 0],
       [0, 0, 0, 0, 0, 0, 0, 0, 0]], dtype=uint8)